This invention pertains generally to the field of cooling systems for electronic apparatus, and in particular to electronic assemblies using cold bars or plates as part of the cooling system for electronic circuitry. While applicable to a variety of electronic fields, it is believed that this invention has its greatest applicability in the field of high speed digital electronic computers, and the description herein of the presently preferred embodiment of the invention illustrates the use of the invention in the computer field.
The continuing trends of electronic circuit miniaturization, and greater complexity and operating speed of large computers have combined to intensify the problem of high heat dissipation and adequate cooling in such computers. Successive generations of integrated circuits have higher packing density in terms of more memory or logic elements within a given integrated circuit size, which is very useful in terms of providing more computer memory and increased computer complexity in a small area, while maintaining the short interconnect path lengths which are required for high speed computer operation. Unfortunately, the increased heat dissipation in such high density devices can exceed the cooling capability of many prior art cooling systems, and upgrading the design of an existing computer by using newer generations of integrated circuits with more functions and more heat generation per chip can exceed the cooling capacity of the system.
Cold bars or cold plates have been used as part of a cooling system, wherein circuit boards or modules are mounted in close thermal contact to the cold bar or cold plate which is cooled by internal refrigerant paths. A successful cooling system for electronic assemblies using cold bars is disclosed in my earlier U.S. Pat. No. 4,120,021, in which the cooling bars have slots along their sides and means are provided for clamping the edges of heat conducting plates of the circuit modules to secure the modules in place and also to conduct away heat generated by the electronic components of the modules. While that system has proved very successful and useful, even greater heat load handling capability is desirable to allow the use of updated electronic modules with higher population of logic or memory circuits per module.